Because the full effect on the brain is still unknown, electroconvulsive therapy is viewed as a last resort treatment for the mentally ill. Still, there are around 100,000 people seeking the treatment each year, including Carrie Fisher.

The Star Wars actress revealed to Oprah that she receives electroshock treatment to deal with her bipolar disorder, and according to the San Jose Mercury News, many others also seek out this treatment when elaborate pill cocktails yield no benefits.

David, a 40-year-old small- business owner in San Francisco, spent about 10 years working to lift what he calls "bone-shattering depression" with 50 to 55 combinations of up to 10 different psychiatric drugs. David is a fictitious name used to protect his anonymity.

"At times, my depression got to the point where it was almost a psychopathic level," he says. David says that he was diagnosed with chronic major depression.